The present invention relates in general to multi-pen type plotter printer and, in more particular, to a multipen type plotter printer having a special mechanism for selection between plural pens.
In the prior art are well known multi-plotter printer, having plural pens, normally mounted on the carriage, for plotting a character or graphic pattern in differently colored ink in response to an information signal. In them, the individual pens are selected for their color of ink and brought into contact at their tip with the surface of monitor paper in which the plotting takes place.
For example, Japanese Patent Application Disclosure No. 68299/1984 discloses a multi-pen plotter printer in which the pens are arranged on the carriage in a row parallel with the direction of travel of the carriage. A signal push member that is also provided on the carriage moves to the rear end of the particular selected pen and pushes it against the monitor paper. This device is advantageous in that the pens need not be provided with a respective push member so that it can be built into a simple construction with the reduced number of parts. However, the device have been found to pose certain problems. First, the carriage cannot be made compact and lightweight, since the entire set of the pen driving system needs to be mounted on it. Secondly, the intrinsic mechanism of the device renders it unsuitable for fast representation of information on the monitor paper and awkward in its pen selecting motion, since, each time a particular pen is selected, full length movement of the carriage along the platen is required to move the push member along with its integrally associated selector shaft into the proper position behind the pen between fixing block members.